The Sturdy Single Chamber Pill Organizer is Made of high quality aluminum alloy with supremely high polished appearance , sturdy and solid -Lightweight, Portable and Handy to secure necessary pills, medications for daily working, carry-on travel, outdoor survival emergency condition or some outdoor sports like Hiking, Camping, Hunting, boating, Fishing . Size: Each small pill box: 0.59”/ 15mm (inner diameter), 1.5”/ 38mm (inner length) Keyring: 0.9”/ 23mm (inner diameter) Tips: Please clean the Pill case completely before your first use. Please note that the bottom is not flat. Check the size before your purchase please. Plase understanding that there may be a little error (±0.2”) of measuring due to manual measurement. TIPS: For any questions or concerns, please don't hesitate to reach out to us. We're here to make things right for you.